Received: by 2002:a05:6a10:2785:0:0:0:0 with SMTP id ia5csp1561411pxb; Sun, 10 Jan 2021 02:40:35 -0800 (PST) X-Google-Smtp-Source: ABdhPJwgVR9CWUwAKxini1tz6Rgv6k1MhssvSeH4pzQh4JsIU8qwHQa8e4TaIxeiXq6RdEIFFVJ/ X-Received: by 2002:a17:906:39d5:: with SMTP id i21mr7326979eje.339.1610275235413; Sun, 10 Jan 2021 02:40:35 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1610275235; cv=none; d=google.com; s=arc-20160816; b=ljkU9xzo41CT/yNbZ2cjgnwq/76c8e1Xo9eR4UuxZVAgcb1XfeUd10dbX1Qcvw+pKj 8blBuGSdb5o9G3YeyN7apITmqKRrA5m9uYKOYijTWI/bY9leQo6xJOKcgVhot50LpVVF BUadRI3XfKMfzjdVZemwF6DGh7Mt2Ke76+hwtyy1zuT9Rlq3TTcK45W1BoGseps7lUOK ZyvM7GpoVHCjD9HfKnpccANrPgl8eQDJzyQ4CvRd/mM5yY8X9VPaBbbj61PXFsi+Vo14 2lyzsR/jdGld1GevMhSYn2GpiUWKCw55wiDLTQzSbHrm7guiLlXwQGTLu+KNlUR8bh7N Fe5A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :message-id:date:subject:cc:to:from; bh=HsShKCkZZSMx5H5qPLwMUeAqmGX98JLxXRhmLDnwews=; b=M40Jr7rKNJw3UpqJgDX5WtsPSzZkYZ95a7bQVaKwVBy01AFFPKpszfaM40CRb2uwN1 zHprE5DWU5+egQl35cDY3rya9ZrKIMRw8brkyJN8izs/bZZs1jA6JH4ePic+p0y4+QLd UFUTXvbla97yfk15Jj8yPee0geqtrJu3PS8QIIFPk+1H+d72WqwHb64zsUsWmSsxGkEw x3HYiBt70HWQfwTQCsXXULD1Py30eH8P9UQxlJCkCs3gz+Cs3vrPofICaX4yZDHW8T+m I2Hr0LxUPB1n1w28Etf1rk2C9CeOakZLyS4VUa0egxCVxOcZudBkQs4cYHHfnOk8oU09 KPLA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id t10si5847665edt.208.2021.01.10.02.40.11; Sun, 10 Jan 2021 02:40:35 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726394AbhAJKiZ (ORCPT + 99 others); Sun, 10 Jan 2021 05:38:25 -0500 Received: from smtp05.smtpout.orange.fr ([80.12.242.127]:27718 "EHLO smtp.smtpout.orange.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726288AbhAJKiZ (ORCPT ); Sun, 10 Jan 2021 05:38:25 -0500 Received: from localhost.localdomain ([153.202.107.157]) by mwinf5d52 with ME id EycA2400E3PnFJp03ycdtu; Sun, 10 Jan 2021 11:36:41 +0100 X-ME-Helo: localhost.localdomain X-ME-Auth: bWFpbGhvbC52aW5jZW50QHdhbmFkb28uZnI= X-ME-Date: Sun, 10 Jan 2021 11:36:41 +0100 X-ME-IP: 153.202.107.157 From: Vincent Mailhol To: Marc Kleine-Budde , linux-can@vger.kernel.org Cc: Vincent Mailhol , Wolfgang Grandegger , "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org (open list:NETWORKING DRIVERS), linux-kernel@vger.kernel.org (open list) Subject: [PATCH 0/1] Add software TX timestamps to the CAN devices Date: Sun, 10 Jan 2021 19:35:25 +0900 Message-Id: <20210110103526.61047-1-mailhol.vincent@wanadoo.fr> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org With the ongoing work to add BQL to Socket CAN, I figured out that it would be nice to have an easy way to mesure the latency. And one easy way to do so it to check the round trip time of the packet by doing the difference between the software rx timestamp and the software tx timestamp. rx timestamps are already available. This patch gives the missing piece: add a tx software timestamp feature to the CAN devices. Of course, the tx software timestamp might also be used for other purposes such as performance measurements of the different queuing disciplines (e.g. by checking the difference between the kernel tx software timestamp and the userland tx software timestamp). Vincent Mailhol (1): can: dev: add software tx timestamps drivers/net/can/dev.c | 2 ++ 1 file changed, 2 insertions(+) -- 2.26.2